JPS5891736A - Granulation of filler - Google Patents

Abstract

PURPOSE:To prepare a granular substance with a high filler content having uniform particle size distribution, by mixing and stirring a filler, crystalline polyolefin powder and a binder having a m.p. lower than that of said polyolefine powder at a specific temp. CONSTITUTION:To 60-90pts.wt. filler (e.g., Al2O3, TiO2)(A) with an average particle size of 0.05-100mu, 5-35pts.wt. crystalline polyolefine powder (e.g., granular polypropylene) (B) having an average particle size (d<a>50) of 150-1,000mu and uniform particle size distribution wherein the powder having a paticle size of (1/2-2) d<a>50 accounts for 90wt% or more and 5-35pts.wt. binder (e.g., atactic polypropylene)(C) having a m.p. 10 deg.C or more lower than that of component B are used as nuclei of a granule and these three components are mixed and stirred at a temp. lower than the m.p. of component B and higher than that of component C to prepare a filler granule wherein filler concn. is 60wt% or more and a proportion of the granule having a particle size of (1/3-3)d<a>50 (where d<a>50 is an average particle size of the granule) is 30wt% or more.

Description

[Detailed description of the invention] The present invention relates to a method for granulating fillers.

More specifically, the present invention relates to a method for obtaining M particles of a filler with a narrow particle size distribution, which is composed of a filler, a crystalline polyolefin powder, and a binder.

Conventional - A filler and, if necessary, a stabilizer, a bleaching agent, and other compounding agents are added to crystalline polyolefin, and the mixture is heated and melted.
Mix the wires and produce pellets.

Molding and processing of this material is generally performed.

However, when attempting to obtain highly filled pellets containing a filler of 11% by this method, the filler is generally finer than crystalline polyolefin powder and has a smaller bulk specific electric charge, so the following precautions must be taken. occurs.

(2) The crystalline polyolefin powder and filler are classified within the hopper or during transfer from hopper to hopper, resulting in non-uniform dispersion of the filler.

” ■ It causes blistering in the hopper, and the extruder C
Otherwise, the firewood is poorly bited into the screw of the kneading machine, and there is not enough time for plasticization, and the granulation ability is significantly reduced, making it impossible to granulate the firewood.

These drawbacks become more pronounced as the amount of filler added increases.
Ru. Therefore, in order to obtain highly filled polyolefin by pelletizing, special consideration is required for the structure of the hopper, the screw structure of the feeder extruder for the mixture of filler and crystalline polyolefin powder, etc., and therefore a large amount of equipment cost is required. Become. In addition, if the amount of filler is increased by -1, the filler will not be uniformly dispersed even if it can be made into pellets, resulting in poor quality and mechanical properties when molded.

For the reasons mentioned above, one filler with a high filler content, especially one that can be used as a masterbatch, is the main component. It is very difficult to produce highly filled granules by heat-melting and pelletizing them.

On the other hand, a method of forming a granular composition containing a relatively large amount of solid powder in a thermoplastic resin without going through the pelletizing process is proposed in Japanese Patent Publication No. 45612/1982 and Japanese Patent Publication No. 8228/1989.

Japanese Patent Publication No. 51-45612 discloses that a thermoplastic 1,1 resin and a solid powder, which is characterized by adding a molten thermoplastic resin to a fluidized state (IJ14) with a strong stirring action on solid powder, A method for producing a granular composition based on the present invention is described. However, in addition to mixing and stirring equipment, such a method requires a separate thermoplastic resin melting system and quantitative ffi'! atomization means.

On the other hand, as stated in the specification of Japanese Patent Publication No. 54-8228,
Thermoplastic polymer material particles and granular filler are mixed, the surface portion of the thermoplastic polymer material particles is gradually melted, and the granular filler is adhered to and mixed with the molten surface portion, and the molten surface portion and filler are mixed together. 1' This is a method of blending a thermoplastic polymer material and a filler by exfoliating a mixture with a 1 agent from polymer material particles.

However, in such a method, the humidity chamber applied to gradually melt the polymer material 'a' is narrow and control is very difficult.

In addition, in this method, as stated in the specification, the filler drop to the polymer material is at a maximum of 2 times the filler/polymer ratio by weight.
This is significantly different from the scope of the present invention. This is because if the amount of filler is increased using such a method, the filler will not be dispersed well and the mechanical properties will be significantly reduced when molded.

Furthermore, in the above two methods, it is difficult to control the particle size and particle size distribution of the particles, and it is difficult to obtain particles with a uniform particle size.

The present inventors have obtained a highly filler-containing granule containing a filler as a main component, in which the filler is uniformly dispersed and has a uniform particle size distribution, and can be used as a filler master patch. As a result of careful study, we found that it consists of a filler, a monocrystalline polyolefin powder, a binder whose ω point is lower than that of the crystalline polyolefin powder, and, if necessary, a predetermined mixture. We have found a method to obtain filler granules consisting of a core of crystalline polyolefin powder and a large amount of filler.

That is, in the present invention, 60 to 90 parts by weight of a filler having an average particle diameter of 0.05 to 100 microns is added to 60 to 90 parts by weight of a filler with an average particle diameter of 150 to 100 OE chromons (d5) as the core of the granules.
o) 5 to 35 parts by weight of a crystalline polyolefin powder having a particle size distribution of 90% or more or 2% by weight and having a particle size distribution of 5 to 35 parts by weight and less than the melting point of the crystalline polyolefin powder 7 (() By adding 5 to 35 parts by weight of a binder having a melting point 10°C lower and mixing and stirring at a moisture content lower than the melting point of the monocrystalline polyolefin powder and higher than the melting point of the binder, the filler concentration can be adjusted. This is a method for producing spray particles of a filler-containing agent in which the proportion of particles having a particle size of 60 parts by weight or more is 900 parts by weight or more.

The filler granules obtained according to the present invention have a uniform particle size distribution and a narrow distribution. Surprisingly, the highly filler-containing granules can be directly molded without pelletizing by simply mixing them with polyolefin powder obtained by a conventional method in a predetermined ratio.

In addition, since the obtained molded product has good filler dispersion, it is comparable in appearance and mechanical properties to molded products obtained by post-molding of conventional pellets (6).
Since it is not subjected to the thermal history of pelletization, its stability and mechanical properties are rather excellent.

The present invention will be described in detail below.

The fillers used in the present invention include silica, silica drift, alumina titanium oxide, iron oxide, zinc oxide, magnesium oxide/pumice powder, water PRized aluminum, magnesium hydroxide/calcium carbonate, magnesium carbonate, calcium sulfate. , barium sulfate, talc, clay, mica, glass peas, inorganic fillers such as carbon black, wood powder, and paint residue. Illustrative are cargo fillers such as pulp, fine powder, and mixtures thereof. The size of the filler is 0.05 to 100μ, preferably 0.05 to 100μ.
It is 50μ.

Further, when obtaining granules, it is preferable to use a finer filler as the particle size of the crystalline polyolefin powder that serves as the core is smaller, so the filler may be appropriately selected based on the average particle size of the granular polyolefin.

In the present invention, homopolymers of ethylene or propylene, random copolymers and block copolymers of ethylene and other α-olefins or propylene and other α-olefins, and these are used as cores during granulation. An example is a mixture of The crystalline polyolefin powder has a uniform particle size distribution with a particle size of .

If the particle size is too small, it becomes easy to scatter, and in particular, if the particle size is less than 100E, it becomes more likely to cause a dust explosion, which is not preferable. On the other hand, if the particle size is too large or the particle size distribution is wide, the particle size of the resulting granules tends to be uneven and dispersion of one filler is insufficient.

Moreover, the closer the shape of the crystalline polyolefin powder is to a spherical shape, the more preferable it is.

The properties of particulate polyolefin are basically determined by the polymerization catalyst used during its production.

As an example of producing a polyolefin with preferable properties suitable for the present invention, a titanium trichloride composition obtained by reducing titanium tetrachloride with an organoaluminum compound and further activation treatment is shown. propylene or propylene and other olefins in an inert solvent or in the substantial absence of an inert solvent in an excess of waste propylene or in a gas phase using a catalyst system consisting of an organoaluminum compound and an electron-donating compound if necessary. It can be obtained by polymerization in the same conditions.

Furthermore, granular polyolefins obtained using a so-called supported catalyst in which a titanium compound is supported on a carrier such as magnesium chloride can also be used.

Examples of titanium trichloride compositions or methods for producing supported catalysts are disclosed in JP-A-47-84478 and JP-A-51.
-Publication No. 76196, Japanese Unexamined Patent Publication No. 58-88289-
JP-A-54-112978, JP-A-54-119
Many proposals have been made, such as No. 576, Japanese Unexamined Patent Publication No. 54-11985, and Japanese Patent Application No. 55-186065 (Sho (9)).

1 of the crystalline polyolefin powder varies depending on the type and shape of the filler, the binder, and the crystalline polyolefin powder, but the amount ranges from 5 to 35 parts by weight per 60 to 90 parts by weight of the filler. It is.

If the amount of counterfeit crystalline polyolefin powder is less than 5 parts by weight, it will be difficult to obtain granules with a uniform particle size distribution.

The binder has the role of supporting a filler and firmly adhering a predetermined abrasive agent to the crystalline polyolefin powder to the core.

It is necessary for the binder to have a melting point at least 10°C lower than the melting point of the crystalline polyolefin powder, which is the core, for manufacturing purposes and for the molding process of the resulting top grains. Please consider and choose accordingly.

First, as a binder, the crystalline polyolefin powder that serves as the core and the crystalline polyolefin powder used when the obtained highly filled granules are made into master pieces and directly molded are used. 10) is preferred.

Is the binder thermoplastic phase IIF? Preferred examples include polyethylene, ethylene-vinyl acetate copolymer, and ethylene-unsaturated carboxylic acid ester copolymer (e.g. ethylene-vinyl acetate copolymer).
methyl methacrylate copolymers, etc.) - ethylene, unsaturated carboxylic acid metal salt copolymers (e.g. ethylene-magnesium or zinc acrylate copolymers, etc.), copolymers of propylene and other primary/fins C propylene - ethylene copolymer, propylene-butene-1 copolymer, etc.), unsaturated carboxylic acid modified products of polyethylene or polypropylene such as maleic anhydride, ethylene-propylene rubber,
Olefin copolymers such as atactic polypropylene.

Petroleum resins include polyalkylene gelylcols such as polyethylene glycol and polypropylene glycol. Particularly preferred are olefin polymers.

In general, polyolefin molded articles to which fillers have been added have higher ductility but lower impact strength than molded articles without fillers.

It is preferable to use an olefin polymer as the binder because the impact resistance strength is less decreased or the strength is improved.

For example, when using granular polypropylene, there is an active polypropylene, polyethylene-propylene-butene-
If fluoropylene rubber or the like is used as a binder, the impact strength will be improved. Particularly, atactic polypropylene is preferred since it has excellent compatibility with polypropylene.

These binders may be used alone or in combination in the chair phase.

The song of the binder differs depending on the seed ode of light 4-cutting and the severity, so it is best to take these into consideration and decide accordingly.

Typically the binder/filler weight ratio is from about 0.05/1.0 to about 0.4/1.0 + preferably from about 0.05/1 to about 0.25/1.

Even if the weight ratio of binder/filler is less than O.n5/1.0, it is possible to firmly adhere the filler and form granules, but this is not preferable because the dispersion of the filler becomes poor.

On the other hand, if it exceeds 0.4/1, it is not preferable because the relative proportion of the binder increases, which may affect physical properties (particularly stiffness).

In the present invention, it is possible to simultaneously add compounding agents such as stabilizers, pigments, and various other auxiliary agents as required, in addition to producing granules.

Stabilizers include various antioxidants and light stabilizers conventionally added to improve the stability and quality of polyolefins, and one or more of these may be used.

Examples of stabilizers include antioxidants such as 2゜6-ditertiarybutyl para-cresol, calcium stearate, tetra[methylene-3-(8,5 ditertiarybutyl-4-hydroxyphenyl)propionate comethane, etc.] As a stabilizer, 2-(2'-hydroxy-5'
-methylphenyl)benzotriazole, 2-hydroxy-4-octylbenzophenone, etc., but are not limited thereto. Various other auxiliary agents (18) include antimony oxide, flame release agents such as dodecachloropentacyclodecane, and lubricants.

Some of these stabilizers have low melting points;
Although these have a similar effect to a binder, fillers, pond stabilizers, pigments, etc. cannot be uniformly and firmly adhered to them by themselves. Further, the pigment is an organic or inorganic pigment used for coloring polyolefin.

An example of the method for granulating the filler of the present invention will be described below.

The equipment used is a mixer equipped with a jacket and an agitator, which allows high-speed fluidization and heating of the contents, and a high-speed mixer for tri-blending granular resin, such as a Henschel mixer. Super mixer (product name,
01 manufactured by Kawada Seisakusho). In this mixer, a predetermined filler, crystalline polyester/fin powder, and binder having a melting point at least 10°C lower than that of the crystalline polyolefin powder are combined with compounding agents such as stabilizers and pigments (14). While mixing, heat to a flow rate slightly higher than the melting point of the binder.

As a result, the dissolved binder adheres firmly and uniformly to the crystalline polyolefin powder, including the filler and compounding agents.

If this is taken out as it is or after being slightly cooled, a highly filler-containing neck granule with good fluidity can be obtained. When producing by this method, it is necessary to use a binder whose melting point is at least 10° C. lower than that of the crystalline polyolefin powder.

The larger the difference in melting point, the better the monkey.

In order to improve the dispersion of the filler and melt the binder in a short time, it is suitable that the thickening agent be as small as possible, but if we take atactic polypropylene as an example, it should have an average particle size of 0.5 mm. However, it can be fully used in the present invention.

Next, the particle size, properties, etc. of the resulting granules can be controlled by appropriately changing the timing of heating, heating, and wetting in the mixing order of the filler, crystalline polyolefin powder, binder, stabilizer, pigment, etc. This is also possible with the present invention.

The filler granules obtained in the present invention have uniform particle sizes and a narrow distribution, and the average particle size of the granules is d. When closed - 90% or more of the granules are 1b
1] It has a particle size within the range of gd50 to 8d50.

The filler agglomerates of the present invention can be manufactured by injection molding, blow molding, extrusion molding, which is generally known without going through a pelletizing process.
Used for forming processes such as sheet forming.

Furthermore, as mentioned above, since the granules of the present invention have uniform particle sizes, they can be directly molded without melting into pellets by simply mixing with polyolefin powder obtained by a general method in a predetermined ratio. In addition, since the filler is well dispersed in the molded product obtained, the appearance and mechanical properties are comparable to molded products obtained by molding conventional pellets (3).

In this way, if the granules of the present invention are used as a masterbatch, the need for pelletization is reduced.

Molding materials with different filler contents can be obtained simply by mixing, and the colors can also be easily adjusted by adding pigments during production.

For example, filled polyolefin molded products obtained by these molding methods have good filler dispersion, and are used for automotive parts such as car heaters, car cooler cases, air cleaner cases, instrument panels, and household electrical appliances such as futons. Suitable for use as outer frames and stands of dryers, vacuum cleaners, refrigerators, speakers, record players, and other parts.

EXAMPLES Hereinafter, the present invention will be specifically explained with reference to Examples, but the present invention is not limited thereto.

Example 1 1) Polymerization content of propylene & stirred stainless steel (17
) The autoclave manufactured by S.A. was purged with nitrogen, and the titanium trichloride solid Ml medium (Bl 501
-0. Hydrogen corresponding to a partial pressure of 5K9/crl was added.

Next, 84 kg of propylene was press-fitted into an autoclave, and the autoclave was kept at 65°C for 2 hours.
Polymerization was continued for hours.

After polymerization, unreacted monomers are purged and methanol 6
0] was added to decompose the catalyst.

The produced polypropylene is sent door to door using a centrifugal filter, and 60
After drying under reduced pressure at 0.degree. C., spherical granular polypropylene having a uniform particle size of 240 mm was obtained. The melting point of this polypropylene was measured with a differential thermal calorimeter (PerkinElmer fR) and found to be 165°C.

This ladle-shaped polypropylene had an average particle size of about 500 microns and a bulk specific gravity of about 0.50.

(2) Manufacture of filler granules (18) Steam of I KgZcrl G was passed through an 800 t super mixer (trade name, manufactured by Kawaguchi Seisakusho) 1 and 2. To this was added the granules obtained by polymerizing propylene in (1). Granular polypropylene 5 odor and 88 kg of talc with an average particle size of 8 microns
and stabilizer (tert-butyl p-cresol'X tetra[methylene-8-(8,5-di-tert-butyl-4-
Hydroxyphenyl) flobionate comethane = 2:
1 (weight ratio)) 100 g, atactic polypropylene (atactic polypropylene manufactured by Sumitomo Chemical ■: 5K11A) as a binder.

Melt viscosity>50000P8)7 Add Kq and 7
The mixture was stirred at 20 r, p, m.

The temperature reached 125°C 10 minutes after starting stirring.

When the stirring was stopped and the inside of the mixer was checked, it appeared that talc had adhered sufficiently, so the mixture was cooled to 80° C. and the contents were extracted, and smooth talc-filled granules with uniform particle size were obtained. The talc adhered uniformly and firmly, and no peeling of the talc was observed even when placed in the palm of the hand and rubbed vigorously with the fingertips.

The contents showed the following particle size distribution.

10 mesh or more L7% 10-28 mesh 98.0'L / 28 mesh or less 3.8π (3) Molding This granule was blended with the granular polypropylene obtained in 1-(1) at the following three ratios.

b) 27,8 72.7 20c
) 54.5 41'i, 5 40
These blended materials were directly molded using an injection molding machine (M-jl12-8J manufactured by Meiki Seisakusho, screw diameter 25 mm, injection amount 1 ounce).

No classification of granular polypropylene and filler particles was observed, and the screw was well-incorporated, and the plasticization time was 12 to 1.
It was 3 seconds. The molded product obtained had a good appearance with no silver streaks or bubbles.

A part of the molded product was hot-pressed into a thin sheet and the state of dispersion of talc was observed, and it was found that the dispersion was good.

Example 2 (1) The same formulation as that used in Example 1-(2) was mixed in the same manner as in Example 1-(2) with the stabilizer 10011. Granules with properties similar to those in Example 1 were obtained.

10 mesh or more 5.2% 10-28 mesh 91.7% 28 mesh or less 3.1. Example 1-(1)
It was blended with the granular polyolefin obtained in the following proportions.

Granules Granular polypropylene (contains charcoal)
2B, 5Wjπ 71.5wt% 2ow
t%b) 57.0 48.0
40 (21) (2) Molding The wet material described in Example 1-(81) was molded under the same conditions as Example 1-(81).
child. The results are shown in Table-1.

Example 8 (1) Formulation Example 1-(granular polypropylene 10K obtained in 11)
g, 25 kg of talc used in Example 1-421, atactic polypropylene 5, and +7 were mixed together with 100 g of a stabilizer in the same manner as in Example 1-(3+).

The particle size distribution of the obtained granules was as follows: 10 mesh or more 1.8%, 10 to 28 mesh 96.8%, 28 mesh or less 1.9%.

(2) Molding Example 8-(11) The granules obtained in Example 1-(8)
It was molded under the same conditions.

The obtained molded product had a very good appearance and the talc was well dispersed.

(22) Example 4 (Production of granules with 13 fillers) Granular polypropylene 5K obtained in Actual Example 1-(1)
y, 85 kg of talc used in Actual Example 1-(2), 100 g of stabilizer, and Sumiryoku (Takusen G301 r low density polyethylene, melting point 110°C) as a binder.
, manufactured by Sumitomo Chemical Co., Ltd.) 30 mesh passing powder 5 Kf
were mixed in a similar manner to Example 1-(2+).

8 minutes after starting PJ, the temperature reached 115℃.

1d Stop stirring, cool to 80℃, and remove contents 7X-1
Granules with a smooth texture were obtained. Particle size distribution of this granule: 10 mesh or more 4.00 10 to 28 mesh 92.59 28 mesh or less
It was 3.5%.

(2) Molding Example 4 - Granules obtained in (1) and seeds + 1/lTi [
The granular polypropylene obtained in ψj1-(1) is granulated/
After blending polypropylene in the ratio of 25.7/74.8, Example 1. -(Molded under the same conditions as No. 83. The results are shown in Table 1.

Examples 5 to 6 (1) Production of filler granules In place of the talc used in I, fff IMJ 1-(2), in Example 5, walrus night with an average particle size of 15 μm was used in Example 6. Filler granules were prepared using silica with a particle size of 10 microns. The particle size distribution of the obtained granules was as follows.

Example 5 Actual example 6 10 mesh or more 3.5 wt% 4.2 wt 10 to 28 mesh 94-298.828 mesh or less 2.8 2.5 (2) Molding these h5A grains as an example 1-Blend with the granular polypropylene obtained in (1) in the following ratio.

Granules Granular polypropylene filler content 5
27.8W% 72.7wt%
2QWt'X6 〃
Table 1 shows the results of molding this blend under the same conditions as in Example 1-(8).

Comparative Example 1 (1) Production of composition A composition was produced in the same manner as in Example 1-(2) except that granular polypropylene was used as the core.

When the temperature reached 125° C., stirring was stopped and the inside of the mixer was checked. A large amount of large particles with a particle diameter of about 11 M or more were produced, and the distribution was wide, making it difficult to perform welding.

10 mesh or more 58% 10 to 28 mesh 329 to 28 mesh or less 109 B Comparative Example 2 Same as Example 1-(2) except that a granular ethylene propylene random copolymer with a melting point of 158°C was used instead of atactic polypropylene. It was done by method.

Talc adhesion was observed even at 158℃ (G25) Since there was no such thing, offshore stirring continued.

Talc adhesion is observed at temperatures exceeding 163℃.
When it was deposited at 65°C, up to one granular polypropylene used as a core began to melt.

Perhaps because of this, the amperage of the mixer suddenly rose, so I turned the mixer down to 1.
I paused. When the inside of the mixer was observed, one block with a particle size of 5 m or more was formed, and direct molding was impossible. Also, there was a large amount of polymer attached to the wall of the mixer.

(26)

Claims (1)

Scope of Claims: When granulating a filler with an average particle size of 0.05 to 100E chromons, 60 to 90 parts by weight of the filler is added with an average particle size of 150 to 1000 microns (d5 (1 )
a crystalline polyolefin powder having a uniform particle size distribution of 50% by weight or more having a particle size of a-d to 2d150, and at least 10% higher than the melting point of the crystalline polyolefin powder.
By using 5 to 85 parts of a filler having a low melting point and stirring at a temperature lower than the melting point of the crystalline polyolefin powder and higher than the melting point of the binder, one filler concentration of 6.
A method for producing granules of filler that is 0.